This document describes a case of a 9-year-old female patient diagnosed with seizures who was found to have an arteriovenous malformation (AVM). Imaging including CT, MRI, and DSA confirmed the presence of an AVM. The patient underwent embolization to treat the AVM. AVMs are abnormal tangled collections of blood vessels consisting of arteries and veins without a capillary bed. They can cause seizures, hemorrhage, and neurological deficits. Treatment options include observation, surgery, embolization, radiosurgery, or a combination depending on the size, location, and severity of the AVM.

1. Arteriovenous malformation
Dr Hieu

2.  Nguyen Ngoc Anh, F, 9 years old, A13
 Clinical diagnosis: seizure.

3. Clinical findings
 Pre-history: cerebral hemorrhage.
 No fever, no headache, no vomitting.
 No paralysis
 seizure: 1 months before being
hospitalized.

6.  DSA >>>> AVM
 Treated by embolization.

7. Definition
 Vascular abnormality constituted by a
complex, tangled wed of afferent
arteries and draining veins linked by
an abnormal dysplastic intervening
capillary bed
 Contrast with a AVF which has direct
fistulous connection without
intervening nidus

8. Etiology
 Initially thought to be congenital
 May be due to aberrant vasculogenesis and
angiongenesis in embryonic
 Failure of the embryonic vascular plexus to
fully differentiate and develop a mature
capillary bed in affected area.
 It is likely that a combination of congenital
predisposition and extrinsic factors lead to
their generation

9. Epidemiology
 In the US general population is
1.4/100,000 per year
 No sexual preference
 Mean age of presentation: 20 – 40
 Account for 3% stroke and 33% primary
intracranial bleeding in young adults.
 1/10 have aneurysms.

10. Angioarchitecture
 Arterial feeder
 Nidus
 Draining vein
 Intervening gliotic parenchyma

11. Angioarchitecture

12. Arterial feeder
 Single or multiple
 Pial, perforating or dural
 Direct feeders supply as terminal
branch
 Indirect feeder supply.

13. Nidus
 The AVM nidus is a compact plexiform of
dysplastic, thin-walled vessels
connecting feeding arteries to draining
veins.
 An AVM nidus can either be globular or
conical in shape; may be compact or
diffuse.
 Within the nidus, arterial blood is
shunted directly into draining veins
without passage through a normal high
– resistance arterial capillary network.

14. AVM syndromes
 Sturge – Weber syndrome.
 Rendu-Osler-Weber syndrome:
autosomal-dominant syndrome of multiple
visceral, mucosal and cerebral vascular
malformation.
 Wyburn-Manson syndrome: unilateral
retinal angiomatosis and cutaneous
hemangioma in an ipsilateral trigerminal
distribution, AVM located in midbrain.

15. Distribution
Based on autopsy findings:
 Cerebral hemisphere: 60 – 70%
 Cerebellum: 11 – 18 %
 Brainstem: 13 – 16 %
 Deep seated: 8 – 9 %

16. Clinical symptoms
 Hemorrhage (54%)
 Seizures (46%)
 Headache (35%)
 Neurological deficits
 Asymptomatic
 Pediatric: hydrocephalus, heart
failure

17. Factors increasing the Risk of
Bleeding
 Most common symptom
 Nidus:
 82% in small AVM
 29% in medium – sized AVM
 12% in large AVM
 Location: deep locations
 Basal ganglia
 Periventricular
 Intraventricular

18. Factors increasing the Risk of
Bleeding
 Deep venous drainage
 Venous stenosis
 Single draining vein
 Feeding artery pressures
 Hemorrhage before

19. Types and size of AVM
 Micro AVM: < 1cm
 Small AVM: 1 – 3 cm
 Moderate AVM: 3 – 6 cm
 Large AVM: > 6 cm

20. CT Scan imaging
 CT is usually the first imaging
modality used to rule out hemorrhage
 Parenchyma calcifications are
observed in 20% of cases.
 Multi - slice CT Scan angiography

21. AVM diagnosis
 Clinical symptoms
 CT scanner
 MRI
 DSA

22. CT Scan
 CT is usually the first imaging
modality used to rule out hemorrhage
 Calcification: 20%
 CT angiography: dynamic contrast

23. CT Scan

24. MRI
 On T1 and T2W images: plexiform
flow void phenomenon.
 T1W with gadolinium: vessels are
enhanced.
 Measure the size and the anatomic
location of the nidus.
 MR angiography: with and without
contrast

25. MRI

26. MRI

27. DSA
 Gold standard to evaluate AVM
 Selective angiongraphy is always
necessary to make a decision to plan
the treatment

29. Different diagnosis
 Venous malformation
 Cavernoma
 AVF
 Telangectasia

31. Classification ( Spetzler Martin)
 Size of nidus
– Small (<3cm): 1
– Medium (3-6cm): 2
– Large (>6cm): 3
 Eloquence area
– Yes: 1
– No: 0
 Deep venous drainage
– Yes: 1
– No: 0

33. Spetzler Martin grading
 Grading AVMs according to their
degree of surgical difficulty and risk
of surgical morbidity and mortality
 There are 5 grades
 Low grade AVM: Grade I, II,
 Medium grade: Grade III
 High grade AVM: Grade IV, V

34. Management
 Observation: large AVM, no bleeding
before
 Surgery
 Embolization
 Radiosurgery
 Combination treatment

35. Surgery
 The most effective treatment: small
and superfacial AVM.
 Pediatric: > 5 years old.
 Remove large, life-threatening
hematoma.

36. Embolization
 First described in 1960 by Luessenhope and
Spence
 A rapidly evolving technique
 Embolic agent: histoacryl with lipiodol,
onyx...
 Complete obliteration by embolization
alone: 40-60% AVM
 Multiple sessions are required most of
cases
 AVM aneurysm.

37. Aims of embolization
 Curative embolization
 Palliative embolization
 Partial embolization
 Pre-operation embolization
 Pre-radio surgery embolization

38. Complication
 Incomplete embolization
 Intracranial hemorrhage
 Ischemia
 Gluing of micro catheter
 Perfusion pressure breakthrough

39. Radiosurgery
 AMVs are inoperable
 Deep AVMs
 Diffusion AVMs

41. Tool for treatment: pros and cons
Embolization Surgery Radiosurg
Low procedural
invasivity
2 1 3
Occlusion capacity 1-2 3 2
Speed of efficacy 2-3 3 1
Long-term reliability 2-3 3 3
Independent from size 3 2 1
Independent from brain
functionality
3 1 2
Independent from
angio-archi
1 2 3
Independent from flow 1 3 2

42. Thanks for your attention!

43. General recommendation
SM grade Deep perfo
vessel
Size 1st
choice 2nd
choice
1 and 2 Sx Rx
3 Absent Sx Rx
3 Present < 3 cm Rx Px
3 Present >3 cm Px Rx + Ex
4 and 5 Absent Ex + Sx Px
4 and 5 Present Px Rx + Ex